Hi, I created a vanilla like vehicle station, this mod is still in the works. This mod allows you to build a station at your base and players can spawn boats at the Maintenance Point. I used for showcase the RHIB mod by "thespacestrider"
by using a custom label, you can add and remove as server owner the boats from this station. As soon as the mod is published I will add a tutorial how to do it for server owners.
If you have any recommendations or feedback please let me know. I highly appreciate it
EASY SETUP
required basic knowledge of Enfusion Workbench
Add
VEHICLE_BOAT
as Authored Label in Authored Labels (SCR_EditableVehicleComponent) in the prefab of your choice
Use the picture down below for visual help 
If the Prefab has this label it will show up at the Maintenance Point.
Disclaimer:
Boat in Picture by TheSpaceStrider - RHIB Mod:
https://reforger.armaplatform.com/workshop/5994614FB5AD35C2-RHIB
https://reforger.armaplatform.com/workshop/65B92E37083CA469-BoatMaintenancePoint